The trip to Mars takes around 6 months. We regularly send people to the International Space Station for 6 months. We are also doing a year-long mission with astronaut Kelly, and the Russians have done several year-long missions (and some even longer), and no big problems with radiation have showed up. ISS has about half the radiation dose as deep space (yes, galactic cosmic rays reach ISS, they're not purely a deep space phenomenon), so these year-long missions simulate the 6-month trip for radiation dose. And after the longest trip, 437 days in orbit, cosmonaut Polyakov actually walked from his capsule (feebly, sure, but still did it) even in full Earth gravity after the fairly rough Soyuz landing because he exercised on orbit. We've made improvements in exercise routines, so I have no doubt that after a much shorter trip and much reduced Mars gravity that astronauts will arrive in fine condition at Mars.

And on the surface of Mars, the dose rate on the surface (assuming you land at low altitude, which is the easiest place to land) is actually lower than ISS, not even counting adding regolith shielding to your habitat.

So there's no doubt in my mind that we can send astronauts to Mars, have them arrive in good shape, and return them back to Earth alive. This will no doubt be fairly risky, but so was Apollo. (And the biggest risks I would be most concerned about as an astronaut wouldn't be radiation or boneloss or whatever else the paranoia du jour is, but the launch, entry/landing at Mars, launch off of Mars, and reentry/landing again at Earth... These very dynamic events, and the procedures surrounding them, are responsible for all in-flight astronaut deaths.)

Several of our machines are operating on or around Mars right now. Mars Reconnaissance Orbiter, Mars Express, Mars Odyssey, MAVEN, India's Mars orbiter, Mars exploration rover Opportunity, and the Curiosity rover.

In a pinch, we could send people to Mars using a similar architecture to some of these robotic vehicles (a scaled up Curiosity entry and descent system and a typical lander type landing would work, though inefficiently... supersonic retropropulsion is much better and much more scalable). We've proven that we can handle the complexity.

Self-sufficiency will take the rest of this century to establish, but there's absolutely no question that sending people to Mars (and back) is possible, and we've proven that we have the technology to do so (and we could've done it in the 1970s, though I'm not sure it would've been a good idea to do an unsustainable Apollo-on-Mars then... reusable vehicles are critically important for scalability and long-term viability... if you develop a reusable architecture, your upfront costs aren't THAT much different than an expendable Mars architecture, but instead of just a handful of individuals, you can send thousands or even tens of thousands and, over the long-term, build the infrastructure necessary for a self-sufficient Mars colony).

So unlike your bird example, we've established this is possible with our technology and that we could've probably done it 40 years ago if we had really wanted to.

Russia uses hypergols for most of their upper stages, and a lander would likely use hypergols anyway (like the Apollo LM). You're describing a non-issue for the Russians.

6 launches isn't complex. We do twice that many flights to ISS every year. In total, we've done over 160 flights to ISS, with Russia doing over half of those.

Anyway, I bet they can do it in 4 Angara launches. Russia is super experienced with in-space rendezvous, autonomous docking, and even more advanced things like propellant transfer (which they do regularly at ISS). 4 or even 6 launches would be no problem.

They'll save a ridiculous amount of money by not building a megarocket like we insist on.

But I agree with the skeptical posters here. Russia always talks about these sorts of things and never does them (not that we're much better). I think it's code-word for "if oil gets over $150/barrel and stays there, then we can do this."

Now that you mention it, it kind of does look like a croissant.

Every billionaire except Elon Musk, who explicitly said recently he wouldn't like to live forever. http://www.vanityfair.com/news...

Have you seen the usual Mars movie from Hollywood? This movie is FAR more realistic than almost any other ones out there. And for true space geeks (of which NASA is full of), the book is fantastic.

The movie isn't some ultra-clever attempt to kickstart public support, although that doesn't hurt. NASA's funding has shrunk as a portion of GDP, as a portion of government spending, and even when just adjusted for inflation even while NASA now is tasked with a far more ambitious mission (to send people to Mars), such that NASA makes up less one half of one percent of the federal budget (this while the public either think NASA has a much larger portion of the federal budget or has been utterly shut down). A little public support wouldn't hurt, though what NASA really needs is the political freedom to rationalize some of their programs (like being freed by Congress to use existing launch vehicles for exploration, like from ULA or SpaceX, instead of spending so much of their budget on SLS) so they can afford to build things like landers and the like instead of things the private/military sectors already have built (like launch vehicles).

Paint them.

You know, technically they /don't/ hand out Nobel Prizes in Economics... It's just a Nobel /Memorial/ Prize.... ;)

But seriously, if you completed 4 years of a theoretical physics Ph.D. but think your MBA was just as challenging... is there a reason why you were able to complete the MBA is less time (presumably)? It's because PhDs in Physics are harder (and possibly not as well compensated as a similar amount of non-Physics-PhD effort for someone intelligent enough to attempt a Physic PhD). Which isn't to say you chose wrong... PhDs in Physics take FOREVER.

But an MBA hardly gets you a PhD in economics...

In all reality, I agree with Musk, here. Being a physicist (even if just undergrad) gives you a much better leg up on spotting fundamental opportunities for improvement in technology than an MBA does. It really does teach you how to spot fundamental relationships and what really matters in a system, while giving you a broad toolset for general problem-solving.

I doubt you would have had as much of a fruitful time pursuing your MBA if you hadn't been trained extensively in Physics beforehand.

For a while in the 1990s and 2000s, disk capacity was getting cheaper and denser faster than transistors were. Going to solid-state would mean a slowing of the rate of storage cost reduction (though there was already a slow-down exacerbated partially by that huge Thailand flood), not an increase. Besides, there are some big problems with scaling down the cell size in NAND flash while keeping the same error rate. If a significantly new technology doesn't rescue flash, we could be looking at an end to rapid cost reduction in data storage, or at least it would be slower than Moore's law.

Which isn't to say I'm arguing that spinning disks will out-compete SSD. I expect solid-state to continue to eat away into spinning disk from here on out. Spinning disks have the big disadvantage of basically being up against pretty hard mechanical limits on latency and seek-time while SSD can improve continually in that regard.

No drives I've ever owned have ever been back-filled with helium, either. Or have ever had 6TB a pop.

Of course I know drives aren't usually sealed. But I find the idea of an external helium supply completely untenable. No one would buy it except maybe a few people who care nothing about cost and all about looking high-tech. It would increase maintenance and upfront costs while adding another single point of failure to the whole system. Way too expensive for dubious gain.

No, there are two approaches that seem reasonable:
1), there's a diaphram or piston which moves (passively) to maintain ambient pressure inside the device while maintaining a helium-tight seal.
or:
2) the drives are built mechanically to withstand whatever pressure differentials are necessary. The easiest way to do this (for the least mass) would be to slightly pressurize the drive above 1 atm.

Helium tends to like to leak out of things. One has to wonder if the power consumption and reliability and speed of the drives will worsen after, say, a decade deployed in the field as the helium gradually is replaced by air. I suppose that has the added benefit for the hard drive manufacturer of a pretty firm drop-dead (or at least significantly reduced performance) date.

But the increased complexity of the technical approach, i.e. cramming more platters (and using fancy technical tricks like using helium) versus just increasing platter areal density, portends an end to the incredibly fast reduction in storage costs over the last three decades.

Another option may be to operate the devices in a soft vacuum (back-filled with a little bit of helium, perhaps). That may further reduce drag. However, I believe the heads rely on an air cushion in order to avoid contact with the platters, so there would be a limit to this.

This is fear-mongering. We are restarting production, and the new Advanced Sterling Radioisotope Generators we have developed produce three times the electricity for the same amount of Pu-238. ...that is, if NASA's budget isn't cut by the Republican house. Sequester is really hampering what NASA can do.

You can swap batteries in half the time it takes to fill a car with gasoline. Standard for all Model S. You're welcome.
http://vimeo.com/68832891

Linus Torvalds himself is a single point of failure... People who rely on Linux being updated in a timely manner should figure out what the probability of him dying is or suffering a debilitating stroke. Then, calculate if it's worth bribing him not to take part in risky activities, pay for a safer car, etc.